Elastic fluid turbine



1931- D. J. BLOOMBERG 1,819,864

ELASTIC FLUID TURBINE Filed March 24, 19:50

Inventor: David Bloonwbel g,

@MY/UITMZ/ His Attorne 10 sive stages. 7 p

In the operatlon of such turbines, leakage passage.

Patented Aug. 18, 1931 v UNITED STATS PATENT OFFICE DAVID J'. BLOOMBERG,OF CHELSEA, MASSACHUSETTS, ASSIGNOR T GENERAL ELEC- TRIC COMPANY, ACOB-PORATION OF NEW YORK ELASTIC FLUID remains Application filed March24, 1930. SerialNo. 438,311,

My invention relates to elastic fluid turbines and more particularly toelastic fluid turbines of the impulse type, which comprise 'a series ofnozzle diaphragms which divide the turbine into stages and bucket wheels1 carried by the turbine shaft and located in the successive stages. Insuch turbines, as is well understood, thenozzles serve to direct theelastic fluid to the buckets of the succeselastic fluid, such as thatwhich; leaks through the shaft packings, finds its way into the spacesbetween the diaphragms and the webs 1 of the wheels, which leakageelastic fluid flows radially outward toward the main stream of elasticfluid passing through the nozzles and buckets. The velocity at which theleakage fluid strikes the main fluid flow is increased over its ordinaryvelocity by frictional contact with the fast moving bucket carryingwheel and, if permitted to flow directly into the main elastic fluidstream,

causes disturbances and cross currents,"thus gending to decrease theefficiency of the turine.

The object of the present invention is to reduce to a minimum, orprevent altogether, losses due to the leakage elastic fluid imping- .30ing with the main stream and at the same time provide means whereby theleakage fluid is fed into the main stream on the discharge side of thebuckets so as to take advantage of the energy stored in the leakagefluid.

working passages are shielded from all deleterious cross currents, andmeans are provided whereby the leakage elastic fluid is introduced intothe working'passage in a path substantially parallel to that of the mainfluid flow so that no disturbances in the fluid flow will arise.

I prefer to shield the working passage by forming integral with thebucket bases, skirts on the inlet and outlet sides. By skirts, I meansprojections formed integral with the bucket bases. These skirts,cooperating with adjacent diaphragms, prevent cross currents fromentering the working Just belowthe skirt means are In accordance with myinvention, the

provided so that the leakage fluid may flow from the inlet side totheoutlet side of the buckets. I prefer to cut grooves in the edges of thebucket bases to form this passageway, although 'it may be formed inotherways. Cooperating with the skirts on the outlet side of the bucketis the adjacent diaphragm which is curved so as to. "permit "theeasyentrance of the leakage'fluid'into the working passage.

For a more detailed description of my invention'reference may be had tothe drawings in which Fig. 1 is a section of a part of the turbineembodying .my invention; Fig. 2 is a perspective view of asingle'turbine bucket showing a groove'cut in its edge just below theskirts; and Fig. 3 is a detail-view of a modification.

- Referring to the drawings, a bucket carrying wheel is shown at 5,supportingbuckets 6 between the diaphragms 7 and 11, the dia phragmnozzle partitions being indicated at 7 and 11*. Protection of theworking passage is aiforded by means of skirts 8 and 9 formed integralwith the bucket bases,-the skirt 8 being on the inlet side and the skirt9 beingon the outlet siden Bythe working passage, I mean the passagewherein the fluid reacts on the curved working portions of thebuckets.

The diaphragms 7 and 11 are secured to casing member'13 andat' the lowerends of the diaphragms 'a usual form of shaft packing is shown at ll'and '15, and balancing holes for the wheel are shown at 16'. .A.certain amount of elastic fluid will escape and flow into the spacebetween the diaphragms. The pressure of the entering leakage fluid andthe pumping actionbetween the elastic fluid and the wheel 5' travellingat a high rate of speed, causes the leakage elastic fluid invention.Inorder to permit the leakage elastic fluid to flow from the inlet sideto the outlet side, passages 10, or suitable ventilating openings areprovided below the skirts. The outwardly travelling leakage elasticfluid is thus directed by the skirt 8 into the passages 10 and throughthe passages to the outlet side. The easy entrance of the leakageelastic fluid into the working passage is obtained by slightly roundingthe entrance edge of diaphragm 11 as is shown at 12. The rounded edge ofdiaphragm 11 cooperates with the skirt 9 so that the leakage elasticfluid may enter the main stream substantially parallel thereto asillustrated.

Instead of forming the skirt 8 as a part of the bucket structure, I mayform it as a part of the diaphragm structure, and this arrangement Ihave illustrated in Fig; 3, wherein the skirt is shown in the form of astrip 18 set in a groove in the diaphragm and serving to deflect theleakage elastic: fluid to passages 19 which correspond to the passages10 in Figs; 1 and 2. Otherwise, the-structure may be the same as thatshown in Figs. 1 and 2. However, in Fig. 3, a skirt corresponding toskirt 9 has been omitted as such a skirt may or may not be used as founddesirable. In Fig. 3, the turbine wheel 20 is shown as being formedintegral with the shaft 21 and the wheel is not provided with balancingholes. My invention has special'utility in connection with aconstruction of this type, because with such a construction all theleakage steam must find its way from stage to stage by passing aroundthe peripheral portion of the wheel since, due to the absence ofbalancing holes, none can escape through such holes.

By my invention the damaging cross currents may not cause disturbance inthe working passage and at the same time all leakage elastic fluidreenters the main fluid flow on the outlet side of'eachrow of buckets.The leakage elastic fluid enters the mainstream substantially parallelto its line of flow and disturbances that occur are negligible.

While I have described the particular embodiment of my invention andcertain apparatus for carrying it into eflect it will be obvious tothose skilled in the art that many modifications may be made withoutdeparting from my invention and I therefore aim in the appended claimsto cover all such modifications as fall within the true spirit and scopeof my invention,

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In an elastic fluid turbine having alternate rows of stationary andmovable fluid directing elements providing a working passage for thefluid, skirts formed integral with said elements to substantially shieldthe working passage from cross currents, means comprising ventilatingopenings whereby leakage fluid may flow from the inlet side of saidmovable fluid directing elements to the outlet side, and meanspermitting the leakage fluid to reenter the working passagesubstantially parallel thereto.

2. In an elastic fluid turbine, a structure comprising a diaphragm and arotor having a row of buckets, said buckets having bases attached to therotor and provided with passages, means torming a part of said structurefor directing leakage elastic fluid to said passages, and means formingpart of said structure permitting the leakage elastic fluid to reenterthe working passage substantially parallel thereto.

3.- In an elastic fluid turbine having stationary and movable fluiddirecting members providing a working passage for the elastic fluid, askirt on one of said members proje'cting therefrom in a directionsubstantially parallel to the flow of the elastic fluid in the workingpassage, the free end of the skirt being in proximity to the adjacentside of the other member, a ventilating passage in the movable memberadjacent said skirt, said skirt preventing leakage fluid from enteringsaid working passage and directing it into the ventilating passage, andmeans at the outlet side of the ventilating passage for directing theleakage fluid into the working passage in a direction substantiallyparallel thereto.

4. In an elastic fluidturbine having stationary and movable fluiddirecting members providing a working passage for the elastic fluid, askirt provided on one of said members and projecting therefrom in adirection substantially parallel to the flow of the elastic fluid' inthe working passage, the free end ofthe skirt, being in proximity to theadjacent side of the other member, a ventilat ing passage in the movablemember adjacent said skirt, said skirt preventing the flow of leakagefluid into the working passage and directing it into the ventilatingpassage, and means provided on said movable member at theoutlet side ofthe ventilating passage for directing-the leakage fluid intothe workingpassages in a direction substantially parallel thereto. 7

5. In, an elastic fluid turbine having stationary and movable fluiddirecting members providing a working passage for the elastic fluid, askirt on one of said members projecting therefrom in a directionsubstantially parallel to the flow of the elastic fluid in the workingpassage, the free end of said skirt being in proximityto the adjacentside of the other member, a ventilating passage in the movable member,said skirt preventing the flow of leakage fluid into the working passageand directing it into the ventilating passage, and means provided onsaidmovable member at the outlet side of the ventilating passage fordirecting the leakage fluid into the working passage in a directionsubstantially parallel thereto, said means comprising a skirt projectingfrom the movable member and provided with a face inclined in thedirection of the flow of 5 the elastic fluid in the Working passage.

In Witness my hand this whereof, I have hereunto set 21st day of March,1930. DAVID J. BLOOMBERG.

